Adjustable stop countersink



Nov. 3, 1942. J. SPIEVAK ADJUSTABLE 5T0? COUNTERSINK Filed July 14, 1941'lllllmlmulllun I N VEN TOR Patented Nov. 3, 1942 amps-rants s'rorooumnasmx Joseph Spievak, Hollywood, Calif., assignor to Lockh Calif.

eed Aircraft Corporation, Burbank,

' Application July 14, 1941, Serial No. 402,329

11 Claims. (01. "Ii-13.5)

This inventionrelates to metal or wood forming tools and moreparticularly to tools for use in drilling, boring or countersinking inany desired material to a predetermined distance or depth. i

This invention finds its most specific application in connection withpowen'driven' tools for :drilling or countersinking operations in metal.

An object of this invention is to provide a drill-'- ing orcountersinking tool which may be accurately adjusted with facility tolimit automatically and precise the depth of a drilling orcountersinking cut to close tolerances. Another ob- Ject of thisinvention is to provide a drilling or countersinking tool which whileaccurately ad- 'justable for depth oi cut will at' the same time providean automatic shield for the cutting-element whereby the materialto beworked and the hands of the operator will be prevented from accidentalcontact therewith during or intermediate the cutting operationsinterval. A further particular object of this invention is to provide amicrometer depth adjustment which will be positive in operation and maybe accurately varied to form or hold positively, predetermined knowncutting dimensions. r

The invention accordingly resides broadly in an adjustablenon-rotatabledepth limiting device adapted to'be semi-permanently fixed to thehousing or frame of a power driven hand drill or the like machine bymeans of which the depth of drilling or countersinking operations can beautomatically and precisely limited. The invention also resides morespecifically in a depth limiting device which is retractable and whichis adapted to provide a guard or housing for the drilling or cuttingelement. The invention further resides in a micrometer type ofdepth-limiting device by means of which cutting or drilling depths canbe precisely regulated and positively maintained.

Other objects and features of novelty will be evident hereinafter.

In the drawing which illustrates a preferred embodiment of theinvention,

Figure 1 is a side view of the general assembly showing the stopcountersink or drilling unit attached to a power driven tool ofconventional design;

Figure 2 is an enlarged sectional view of the device of the inventiontaken on line 2-2 of Figure 1;

Figure 3 is a fragmentary detail of the retract- Figure 4 is across-sectional view taken on line 4-4 of Figures 1 and 2f Figure 5 isan optional form of cutting tool.

In the figures, I0 is the hand grip and, II the housing of the primemover of a power operated hand -drill unit whichv may be electrically orpneumatically operated as here illustrated. The

said unit is of conventional design except that it is provided with athreaded connection l2 fixed to the outer end l3 of the unit housing IIto which the device of this invention is adapted to be semi-permanentlycoupled.

The body member 15' of the stop-countersink unit is cylindrical ingeneral form and is provided at the inner end with suitable threads l6by means of which it is adapted to make threaded connection to thebefore mentioned/threadedconnection ll of the prime mover housing ii andby whichit is normally non-rotatably fixed and supported in coaxialrelation to the prime mover shaft or spindle ll.

' tially less than either said intermediate shoulder II or body memberii, the outside cylindrical surfaces of said body member i5, shoulder l8and sleeve guide being coaxially'arranged.

The body member I! is provided with a concentric internal bore 20 ofvariable diameter adapted to accommodate coaxially a rotatable tooladapter mandrel 2| which in turn makes a screwed coupling'at 22 with theprime mover shaft ll. The mandrel is provided at the outer end with a'taper chuck- 24 adapted to receive the tapered shank 25 of a cutter toolor drill such, for example, as a countersink drill 26.

A stop sleeve 21 is adapted to make a slidin Y fit. upon the guidemember l9 and is retained thereon with limited freedom for axialmovement for reciprocation by means of a screwed stop pin 29 whichpasses through the stop sleeve and extends laterally with a slip fitinto a longitudinally positioned slot 30 in the guidemember IS. Thesaid'stop sleeve 21- is urged outwardly and normally maintained in anextended position upon the guide member l8 and against the stop pin 29as shown in Figure 2, by means of a compressed coil spring 3| which ispartially retained at one end in a counterbored annular recess 32provided within the inner end of said stop sleeve 21 and which reacts atthe opposite end against the annular shoulder)! formed at the Junctionl5 carries or includes 2 of the sleeve guide member I 9 and theintermediate body member i8. The outer portion of the stop sleeve 21which extends beyond the endof the sleeve guide i9 and which normallysubstan-v mating a truncated cone, is carried upon and 'makes threadedconnection at 23 with the threaded intermediate portion 18 of the bodyiii. The stop nut 39 is counter-bored at 40 in the outer end toaccommodate the retraction of the stop sleeve 21 and toy form a narrowannular shoulder 4| which serves as a stop to limit the inward orretractive motion of the said stop sleeve. The inner threaded portion ofthe bore of the stop nut 39 is provided with a plurality of uniformlyshaped axially positioned grooves or splines 42 which, acting inconjunction with spring actuated balls 43 retained in radially po-'sitioned drilled recesses 41 in the intermediate body portion i 8,serves to lock the stop nut in predetermined angular positions upon thecommon threads.

A set screw 44 serves to semi-permanentlylock the stop nut 39 againstmovement and to thereby retainany resired adjustmentthereof.

A pair of drilled holes '45 and 48 are provided in .the periphery of thebody portion l of the device for the application of a special wrench formaking or breaking the threaded connection at l 2,|9 with the primemover housing.

The operation of the apparatus or device of the invention is as follows:If, for example, it is desired to countersink holes previously drilledin a piece of sheet metal thetool is applied to the drilled sheet metalas illustrated in Figure 2 with the tip 34 of the countersink cutterhead 29 inserted in a drilled hole 49 of the sheet 49 and the annularface 50 of the outer end of the stop sleeve 21 is then brought to bearsquarely upon the adjacent surface ofthe sheet. Upon application ofsuflicient force upon the tool and against the sheet metal surface toovercome the compressive force of the coil spring 3| the said stopsleeve 21 is forced to retract from its out most position as shown inFigure 2 and into the bore 40 of the stop nut 39 until said stop sleevehas moved inwardly along the guide sleeve I9 to a point where the innerend 28 of the stop sleeve is brought up against the shoulder 4! of thestop nut. This having been done the beveled cutter edges 5| of thecountersink head 26 will have penetrated into the sheet face surroundingthe drilled hole to form 'an angular sinking operations may be performedin a single operation. Ordinarily, however, when only countersinkoperations are desired to be performed upon previously drilled sheets, acutter head is employed, as illustr ated in Figure 5,

" which, instead of having a pilot drill as shown at 34 in Figure 2employs a smooth ended pilot knob 53 which serves only to center andguide the countersink cutters into the drilled holes 48., The knob 53which is removable, has a diameter only slightly less than the hole inthe .ward or backward upon the threads on the intermediate body memberl8 and thus to vary the clearance between-the inner end 28'of the stopments are possible which may be employed aslock notches in the stop nutwith three equally angularly spaced ball locks in the intermediate bodymember l8, one click .of the ball lock, or in other words a rotation ofthe stop nut through an angle equal to one-third of the angularseparation of the notchesv whichis onethirti'eth of a completerevolution, will move the stop nut axially approximately .00103 inch.

Other lock nut threading and ball lock arrangedesired to give micrometeradjustments of any suitable proportions or fractions of an inch. Forexample, with ,50 threads per. inch on the stop nut, ten notchesand fourequally spaced ball locks, each ball lockclick upon rotation of the stopnut will move the stop nut axially exdepression or countersunk hole asshown at 52.

The depth to which the said countersink is actly .001 inch. Theretractive adjustment of the stop sleeve and thus the correspondingdepth of a drilled hole or countersink out can be readily adjusted inpositive steps of .001 inch to any desired predetermined depth withinthe maximum adjustment range of the device.

The apparatus of this invention, while most particularly described"hereinbefore as being adapted to countersinking operations may also beemployed with equal facility and advantage to straight drillingoperations where it is desired to accurately control the. depth of thehole drilled. The apparatus can also be. employed for burring drilledholes and/orvarious other cutting and grinding operations. Therefore,when in the specificationsand claims the term countersinking isemployed, it is] to be understood that the term is not limited but mayinclude within its meaning, drilling, burring, grinding and othersimilar cutting operations requiring precise depth regulation.

The invention is applicable" to the beforementioned operations in metal,wood and various plastics, resins and the like-workable compositions andmaterials.

The countersink stop mechanism of this invention'is preferably made ofsteel'which may be suitably heat-treated and/or hardened, but othermaterials, such as aluminum, aluminum alloy,

unit together with the prime mover to operation with one hand. Aparticular advantage the apparatus resides in the micrometer type ofmeans for regulating the depth of cut.

The foregoing is merely illustrative of the apparatus oi'the inventionand is not intended to be limiting. The invention'includes any apparatusor device which accomplishes the same results within the scope oi theclaims.

I claim: 1. A stop countersink unit comprising in combination a bodymemberadapted to be fixedlyv coupled at the innerend with a prime moverhousing, a retractable sleeve reciprocatably attached to and extendingbeyond the outer end 01' said body member and adapted tov substantiallyhouse a rotatable cutting tool therein when said sleeve is in anextended position and means to' limit adjustably the retractability ofsaid sleeve with respect to said body member whereby a predeterminedlimited length of cutting tool may be exposed.

2. A stop countersink unit comprising in combination a body memberadapted to be fixedly coupled at the inner end with a prime moverhousing, a retractable sleeve reciprocatably attached to and extendingbeyond the outer end of .said body member and adapted to substantiallyvhouse 'arotatable cutting tool therein when said sleeve is in anextended position, a spring adapted coupled at the inner end with aprime mover housing, said body memberhaving an axially positioned boreadaptedto house a coaxially positioned rotatable, tool mandrel extendedfrom said prime mover, a retractable sleeve reciproca-- tablyattached toand extending beyond the outerend of said body member and adapted tosubstantiaily house therein a rotatable cutting tool carried in theouter'end of said mandrel when mined limited length at cutting tool maybe ex-- said sleeve is in an extended position, a spring adapted 'to;urge and normally maintain said sleevein a fully extended position withrespect to said body member, an intermediate threaded posed.

6. Apparatus according to claim 5 with means to maintain the said bodymember, retractable sleeve and stop nut normally non-rotatable withrapect to said prime mover housing during operto urge and normallymaintain said sleeve in a fully extended position with respect to saidbody member, and means to limit adjustably the retractability of saidsleeve with respect to said body member upon application of retractiveforce to the outer end of said sleeve and against said spring whereby apredetermined limited length- .of cutting tool may be exposed.

' 3. A stop countersink unit'comprising in combination a body memberadapted to be fixedly coupled at the inner end with a prime moverhousing, said body member having an axially positioned bore adapted tohouse a coaxially positicned rotatable tool mandrel extending from saidprime mover, a retractable sleeve reciprocatably attached to andextending beyond the outer end of said body member and adapted tosubstantially house therein a rotatable cutting tool carried in saidmandrel when said sleeveis in an extended position, and means to limitadjustably the retractability of said sleeve with respect to moverhousing and adapted to substantially house ationoi the tool.

7. A stop countersink unit comprising in combination a prime moverhaving a stationary housing, a retractable tubular sleeve non-rotatablybut reciprocatably attached to said prime a rotatable cutting tooltherein when said. sleeve is in an extended position and means to limitadsaid body member whereby a predetermined I I limited length of thecutting tool may be exposed.

4. A stop countersink unit comprising in combination a body memberadapted-to be fixedly coupled at the inner end with a prime moverhousing, a retractable sleeve reciprocatably attached to and extendingbeyond the outer end of said body member and adapted to substantiallyhouse a rotatable cutting tool therein when said sleeve is in anextended position, an intermediate threaded shoulder portion of saidbody,

member, a stop nutmaking threaded connections with said shoulder andadapted to adjustably limit the retractability of said sleeve withrespect 'to said body member, a spring actuated ball lock justably theretractabiiityoi said sleeve with respect to said housing whereby apredetermined limited length 0! cutting tool may be exposed.

- 8. A stop countersink unit comprising in combination a prime moverhaving a stationary.hous-' ing and a rotatable shaft, a body memberadapted to be fixedly coupled at the inner end with the prime moverhousing, said body member having an axially positioned bore adapted tohouse a coaxially positioned rotatable tool mandrel attached to andextending from said prime mover shaft, a retractable sleevereciprocatably attached to and extending beyondthe outer end ofsaid bodymember and'adapted to substantially house therein a rotatablecuttingtool carried in the outer end of said mandrel when said sleeve is in anextended position and means to limit adjustably the retractability ofsaid sleeve with respect to said body member whereby a predeterminedlimited length of cutting tool may be exposed.

9. Apparatus according to claim 7 in which the means to limit adjustablythe retractability of the said sleeve comprises an adjustable micrometerstop screw device.

10. A stop countersink unit comprising in com-' bination a prime moverhaving a stationa housing and a rotatable shaft, a body memb adapted tobeflxedly ,coupled at the inner end with the associated with saidintermediate body. portion and adapted to lock said stop nut againstrotation in predetermined angular positions to limit adjustably'theretractability'oi said sleeve with respect to said body member whereby apredeterprime mover housing, said body member having an axiallypositioned bore adapted to house a co-- axially positioned rotatabletool mandrel attached to and extending from said prime mover shalt, a

retractable sleeve reciprocatablyattached to and mined limited length oicutting tool may be exposed.

5. A stop countersink unit comprising in comextending beyond the outerend of said body member and adapted to substantially house therein arotatable cutting tool carried in the outer end of said mandrel whensaid sleeve is in an extended position, a spring adapted to urgebination a body member adapted to be fixedly 1d and, normally maintainsaid sleeve in ai'ullyex- 4 v A v asomoi tended position with respecttosaid body member, tion of a retractive force to the outer endtof said Van intermediate threaded shoulder portion of said sleeve whereby apredetermined limited length of body member, a stop nut making threadedcon cutting tool may be exposed,

nection with said shoulder, and a spring actuated 11. Apparatusaccording to claim 7, with means ball lock associated with saidintermediate body 5 to limit adjustably, in predetermined dimensionalp'ortionand adapted to lock said stop nut against steps, theretractability of said sleeve with re- I rotation in predeterminedangular positionsto spect to said body member,

limit adjustably the retractability of said. sleeve 4 with respect tosaid body member upon applica- JOSEPH SPIEVAK.

